Filter element, air cleaner, and methods

ABSTRACT

A filter arrangement includes a filter element, a frame construction secured to the filter element, and a handle member secured to the filter element. In preferred embodiments, the handle member is secured to the frame construction. Preferably, the filter element includes a central core member, wherein fluted filter media is coiled around the central core member. Preferably, the central core member includes a plurality of corrugations, wherein the corrugations mateably engage at least some flutes. Preferably, the handle member is integral with the central core member, and also includes a fastening member for connection to a frame construction on the filter element. Methods for cleaning air and servicing an air cleaner preferably include constructions as described herein.

This application is a continuation of application Ser. No. 10/077,526,filed Feb. 15, 2002 issued as U.S. Pat. No. 6,547,857; application Ser.No. 10/077,526 is a continuation of application Ser. No. 09/434,523,filed Nov. 5, 1999, issued as U.S. Pat. No. 6,348,084. The disclosuresof application Ser. Nos. 09/434,523 and 10/077,526 are incorporatedherein by reference.

TECHNICAL FIELD

This disclosure describes filter constructions for filtering fluids,such as gas or liquid. In particular, this disclosure describes a filterelement having a centerpiece, methods for servicing an air cleaner, andmethods for constructing a filter element having a centerpiece.

BACKGROUND

Straight through flow filter elements have been used in systems forcleaning fluid passing therethrough. Straight through flow filterelements typically will have an inlet face and an oppositely disposedoutlet face. In this manner, fluid flows in one certain direction uponentering the filter element at the inlet face and will have the samedirection of flow as it exits the outlet face. Typically, straightthrough flow filter elements will be installed in a duct or housing ofsome type. After a period of use, the filter element will requireservicing, either cleaning or a complete replacement. If it is difficultor inconvenient to service the filter element, the user may delay theproper servicing, which can cause damage to whatever system is beingfiltered.

Improvements to straight through flow filter elements are desirable.

SUMMARY OF THE DISCLOSURE

The disclosure describes a filter arrangement including a filterelement, a frame construction secured to the filter element, and ahandle member secured to the filter element. In preferred arrangements,the filter element includes a plurality of flutes, wherein each of theflutes have a first end portion adjacent to a first end of the filterelement, and a second end portion adjacent to a second end of the filterelement. Selected ones of the flutes are open at the first end portionand closed at the second end portion, while selected ones of the flutesare closed at the first end portion and open at the second end portion.

In preferred arrangements, the handle member is secured to the frameconstruction.

In certain preferred embodiments, the filter element includes a centralcore member, wherein the plurality of flutes are coiled around thecentral core member. Preferably, the handle member will be secured tothe central core member. In preferred embodiments, the central coremember includes a plurality of corrugations, wherein the corrugationsmateably engage at least some of the flutes.

The disclosure also describes a center board for use in a filterelement. Preferred center boards include an extension having first andsecond opposite ends, and a region of corrugation located on theextension between the first and second ends. The region of corrugationis constructed and arranged to mate with fluted media of a filterelement.

Preferably, the center board will include a handle member forming thefirst end, and a fastening member forming the second end. The fasteningmember is preferably constructed and arranged to connect to a frameconstruction of the filter element.

The disclosure also describes an air cleaner including a housing and afilter element removably positioned in the housing. The housing includesa body member and a cover. The cover includes a projection extending ina direction toward an interior of the body member. The filter elementpreferably includes a center board extending at least partially into thefilter element. Preferably, the center board includes a first portionaxially extending from a flowface of the filter element. In preferredembodiments, the projection of the cover will engage the first portionof the center board, when the filter element is operably installed inthe interior, and when the cover is operably oriented over an open endof the body member.

The disclosure also describes a method for servicing an air cleaner. Themethod includes providing a filter element installed in a housing. Thefilter element includes a frame construction secured thereto. The methodincludes a step of grasping a handle secured to the frame construction,and pulling the handle to remove the filter element from the housing.Preferred methods will utilize filter element constructions ascharacterized herein.

Methods for constructing air filter elements are also described. Inpreferred methods, there is a step of providing a center board havingfirst and second opposite ends and a region of corrugation at leastpartially located between the first and second ends. Selected flutes offluted filter media are aligned with the region of corrugation. Thefluted filter media is then wound around the center board.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of one embodiment of a system having anengine with an air intake system and an air cleaner constructedaccording to principles disclosed herein.

FIG. 2 is a schematic, cross-sectional view of one embodiment of an aircleaner, including an air cleaner housing and a filter element operablyinstalled therein, constructed according to principles of thisdisclosure.

FIG. 3 is a schematic, exploded, side elevational view of the aircleaner depicted in FIG. 2.

FIG. 4 is a schematic, perspective view of one embodiment of a portionof filter media usable in the filter element depicted in FIGS. 2 and 3.

FIG. 5 is a schematic, perspective view of the embodiment of the airfilter element depicted in FIGS. 2 and 3.

FIG. 6 is a schematic, perspective view of one embodiment of the filterelement depicted in FIG. 5, and shown from an opposite end.

FIG. 7 is a schematic, exploded, side elevational view of one embodimentof the filter element depicted in FIGS. 5 and 6.

FIG. 8 is a top plan view of one embodiment of a center board usable inthe filter elements depicted in FIGS. 2, 3, and 5-7.

FIG. 9 is an enlarged cross-sectional view of the center board of FIG.8, and taken along the line 9—9 of FIG. 8.

DETAILED DESCRIPTION

A. FIG. 1, System of Use

The air cleaner arrangements and constructions disclosed herein areusable in a variety of systems. FIG. 1 depicts one particular system,shown schematically at 20. In FIG. 1, equipment 22, such as a vehicle,having an engine 24 with some defined rated airflow demand, for example,about 500-700 CFM, is shown schematically. Equipment 22 may comprise abus, a highway truck, an off-road vehicle, a tractor, or marineapplication such as a powerboat. Engine 24 powers equipment 22, throughthe use of an air, fuel mixture.

In FIG. 1, airflow is shown drawn into the engine 24 through an airintake system 26. The air intake system 26 includes an air cleaner 28,and air is taken into the air cleaner 28 at arrow 30.

A primary filter element 32 is shown upstream of the engine 24 to removeparticles and contaminants from the air. Downstream of the primaryfilter element 32 may be an optional safety element 34. The safetyelement 34 is also upstream of the engine 24 to remove any particles andcontaminants that did not get removed by the primary element 32.

The air is cleaned in the air cleaner 28, and then it flows downstreamat arrow 36 into the intake 26. From there, the air flows into theengine 24 to power the equipment 22. An optional turbo 38 may be used toboost the power.

B. Overview of Air Cleaner

One example of an air cleaner 28 usable in system 20 is shown incross-section in FIG. 2 at 50. In general, the air cleaner 50 holds aremovable and replaceable filter element 52 within its interior 54. Theair cleaner 52 includes an inlet 56 and an outlet 58. Air to be cleanedis directed into the air cleaner 50 through the inlet 56, through thefilter element 52, and then out through the outlet 58. The air willtypically then be directed into an air intake system, such as intake 28for engine 24. The filter element 52, when operably installed in thehousing 51, will remove substantial portions of particulate matter fromthe air or gas flow stream directed therethrough.

Still in reference to FIG. 2, the filter element 52 is configured topermit straight through flow. By the term “straight through flow,” it ismeant that the fluid flows directly through the filter element 52,entering at an inlet face 60 and exiting at an oppositely disposedoutlet face 62, wherein the direction of fluid flow entering the inletface 60 is in the same direction of fluid flow exiting the outlet face62. For example, the filter element 52 has a first end 64 and anopposite, second end 66. In the arrangement depicted in FIG. 2, thefirst end 64 will correspond to an upstream end inlet face 60, while thesecond end 66 will correspond to a downstream end outlet face 62. Otherarrangements may include the first end 64 as corresponding to the outletface, while the second end 66 corresponds to the inlet face. Thestraight through flow allows gas to flow into the first end 64 and exitthe second end 66, such that the direction of the air flow into thefirst end 64 is the same direction of air flow that is exiting thesecond end 66. Straight through flow patterns can reduce the amount ofturbulence in the gas flow.

Still in reference to FIG. 2, there is also a handle member 70 securedto the filter element 52, to assist in servicing the air cleaner 50. Inparticular, the handle member 70 assists in the convenient removal ofthe filter element 52, to service the air cleaner 50. The handle member70 is described in further detail below. FIG. 2 also illustrates a frameconstruction 72 secured to the filter element 52. As will be describedin further detail below, the frame construction 72, in preferredembodiments, supports a seal member 74 to create a seal, preferably aradial seal 76, between the filter element 52 and the housing 51. Theframe construction 72 also, in preferred embodiments, engages the handlemember 70. This is discussed further below.

C. The Housing

Attention is directed to FIGS. 2 and 3. The housing 51 preferablyincludes two pieces, a body member 80 and a removable cover 82. Bodymember 80 defines the open interior 54 (FIG. 2) and an open end 84. Theopen end 84 is for receiving the filter element 52 therethrough. Thecover 82 is selectively movable from the open end 84 of the body member80, in order to provide access to the interior 54. For example, duringservicing of the air cleaner 50, the cover 82 can be removed to provideaccess to the filter element 52.

The cover 82 includes fasteners, such as bolts 86 (FIG. 3) for securingthe cover 82 to the body member 80.

In general, the air cleaner 50 includes a stay member 87 that will helpto keep the filter element 52 properly oriented in the body member 80.The stay member 87 will also function as an indicator to communicate tothe user if the user has not initially properly installed the filterelement 52 in the body member 80. By “properly installed,” it is meantthat the filter element 52 is oriented and seated within the interior54, and the radial seal 76 is in place.

While a variety of embodiments for the stay member 87 are contemplated,in the particular embodiment illustrated, the stay member 87 comprises aprojection 88 extending from the cover 82 in a direction toward theinterior 54, when the cover 82 is operably oriented over the open end 84of the body member 80. The projection 88 helps to hold the filterelement 52 in place within the body member 80, during operation.Vibration and other factors could try to knock the filter element 52loose within the housing 51 during operation. The projection 88 helps tokeep the filter element 52 properly seated and installed.

In the embodiment illustrated in FIG. 3, the projection 88 includes anelongate extension 90, extending from and integral with the cover 82. Inparticular, the extension 90 is located at about the center 92 (FIG. 2)of the cover 82. The extension 90 is preferably angled between about80-100°, preferably about 90°, relative to the inside surface 94 of thecover 82. The extension 90 includes a generally flat, element engagingend 96. As such, the extension 90 comprises a cantilevered beam 97 witha fixed end at the cover 82 and a free end at the element engaging end96. Preferably, the extension 90 will have a width 98 (FIG. 2) that issmaller than a void 100 (FIG. 2) formed in the handle member 70.

In reference again to FIG. 2, the body member 80 has in its interior 54a first annular region 102 and a second annular region 104. The secondannular region 104 is smaller or reduced relative to the first annularregion 102. This creates a shoulder 106 at the transition between thesetwo regions. There is also an end wall 108 terminating the secondannular region 104. The second annular region 104, together with the endwall 108, forms a seat 110 for receiving the frame construction 72 withthe seal member 74. The filter element 52 is properly oriented in thehousing 51, when the seal member 74 is compressed against the secondannular region 104 to form radial seal 76 against the second annularregion 104. The end wall 108 helps to orient the filter element 52, andprevent it from being pushed downstream, past the second annular region104.

It should be appreciated that the radial seal 76 helps to preventunintended gas flow from flowing around the filter element 52 andavoiding the filtering affect of the filter element 52. That is, theradial seal 76 helps to force the gas flow coming through the inlet 56to travel through the filter element 52, in order to reach the outlet58.

The body member 80 also includes a sloped wall portion 112 extendingfrom the end wall 108 toward the outlet 58. The sloped wall portion 112helps to direct the filtered or cleaned gas from the outlet face 62through the outlet 58.

D. The Filter Element

The filter element 52 will now be described in further detail. Attentionis directed to FIG. 4. FIG. 4 is a schematic, perspective viewdemonstrating the principles of operation of certain preferred mediausable in the filter construction herein. In FIG. 4, a flutedconstruction is generally designated at 122. Preferably, the flutedconstruction 122 includes: a layer 123 of corrugations having aplurality of flutes 124 and a face sheet 132. The FIG. 4 embodimentshows two sections of the face sheet at 132A (depicted on top of thecorrugated layer 123) and at 132B (depicted below the corrugated layer123). Typically, the preferred fluted construction 122 will include thecorrugated layer 123 secured to the bottom face sheet 132B. When usingthis fluted construction 122 in a rolled construction, it typically willbe wound around itself, such that the bottom face sheet 132B will coverthe top of the corrugated layer 123. The face sheet 132 covering the topof the corrugated layer 123 is depicted as 132A. It should be understoodthat the face sheet 132A and 132B are the same sheet 132.

When using this type of fluted construction 122, the flute chambers 124preferably form alternating peaks 126 and troughs 128. The troughs 128and peaks 126 divide the flutes into an upper row and a lower row. Inthe particular configuration shown in FIG. 4, the upper flutes formflute chambers 136 closed at the downstream end, while flute chambers134 having their upstream end closed form the lower row of flutes. Thefluted chambers 134 are closed by a first end bead 138 that fills aportion of the upstream end of the flute between the fluting sheet 130and the second facing sheet 132B. Similarly, a second end bead 140closes the downstream end of alternating flutes 136. In some systems,both the first end bead 138 and second end bead 140 are straight allalong portions of the fluted construction 122, never deviating from astraight path.

When using media constructed in the form of fluted construction 122,during use, unfiltered fluid, such as air, enters the flute chambers 136as indicated by the shaded arrows 144. The flute chambers 136 have theirupstream ends 146 open. The unfiltered fluid flow is not permitted topass through the downstream ends 148 of the flute chambers 136 becausetheir downstream ends 148 are closed by the second end bead 140.Therefore, the fluid is forced to proceed through the fluting sheet 130or face sheets 132. As the unfiltered fluid passes through the flutingsheet 130 or face sheets 132, the fluid is cleaned or filtered. Thecleaned fluid is indicated by the unshaded arrow 150. The fluid thenpasses through the flute chambers 134, which have their upstream ends151 closed to flow through the open downstream ends out the flutedconstruction 122. With the configuration shown, the unfiltered fluid canflow through the fluted sheet 130, the upper facing sheet 132A, or thelower facing sheet 132B and into a flute chamber 134.

The fluted construction 122 is typically wound into a rolled or coiledform, such as shown in FIG. 5. A variety of ways can be used to coil orroll the fluted construction 122. In constructing the filter element 52,typically the fluted construction 122 is wound around the handle member70 in a coil or spiral pattern thereabout. This is described in furtherdetail below. Referring again to FIG. 5, note the cross-sectional shapeof the filter element 52 is non-circular. While the cross-section couldbe circular, due to the geometry of the volume that the filter element52 is installed within, it is sometimes convenient to have anon-circular cross-section. This cross-section permits a relativelylarge amount of media to economically occupy a small volume. In somepreferred constructions, the cross-sectional configuration of the filterelement 52 will be ob-round. In the particular embodiment shown in FIG.5, the filter element 52 defines a cross-section that is racetrackshaped. By “racetrack shaped,” it is meant that the filter element 52defines a curved (in some embodiments, semicircular) end 160 and anopposite curved (in some embodiments, semicircular) end 162. The curvedends 160 and 162 are joined by a pair of straight segments 164, 166.

When using rolled constructions, such as the filter element 52, thesystem designer will want to ensure that the outer periphery of thefilter element 52 is closed or locked in place to prevent the flutedmedia construction 122 from unwinding. There are a variety of ways toaccomplish this. In some applications, the outer periphery 168 iswrapped with a periphery layer 170. The periphery layer 170 can be anon-porous material, such as plastic with an adhesive on one side. Insome embodiments, the periphery layer 170 may be a tough, durablematerial such as chip board or mylar. Still in other embodiments, theouter layer 170 may be a permeable media.

In reference again to FIG. 2, the filter element 52 is shown installedin the housing 52. In the arrangement shown, air flows into the housing51 through the inlet 56, through the filter element 52, and out of thehousing 51 at the outlet 58. The seal member 74 is needed to ensure thatair flows through the filter element 52, rather than bypass it.

E. The Frame Construction and Sealing System

The frame construction 72 provides a support structure or backingagainst which the seal member 74 can be compressed to form radial seal76 with the body member 80 of the housing 51.

Attention is directed to FIGS. 5-7. The frame construction 72 includes aframe 180. The frame 180 may be a variety of shapes. In the particularembodiment illustrated in FIGS. 5-7, the shape of the frame 180 isgenerally ob-round or racetrack shaped. The frame 180 is convenient inthat it is arranged and configured for attachment to the outlet face 62of the filter element 52.

The preferred frame 180 depicted includes a band, skirt, or dependinglip 182 that is generally sized to mateably engage and receive thesecond end 66 of the filter element 52. The depending lip 182 preferablyextends radially around the outlet face 62, such that the depending lip182 extends inboard a distance over the filter element 52. In preferredarrangements, the frame 180 will be secured to the filter element 52 atthe interface between the lip 182 and the inboard region that the lip182 extends along the periphery layer 170.

The frame 180 also includes an annular sealing support 184 (FIG. 2)extending from the lip 182. Between the sealing support 184 and the lip182, the frame 180 includes a step 186. The step 186 provides atransition area between a larger dimension of the lip 182 and a reduceddimension of the sealing support 184.

When constructed according to principles described herein, the sealingsupport 184 provides a rigid support surface for the seal member 74. Theseal member 74 is preferably constructed and arranged to be sufficientlycompressible to be squeezed or compressed between the sealing support184 of the frame 180 and the second annular region 104 of the bodymember 80. When compressed between the support surface 184 and thesecond annular region 104, the radial seal 76 is formed between thefilter element 52 and the body member 80 of the housing 51.

A variety of ways are possible to secure the seal member 74 to thesealing support 184. One particularly convenient and preferred way is bymolding the seal member 74 to engage, cover, or overlap both the innerportion 188 and the outer portion 190 of the sealing support 184,including the end tip 192. One example of this is depicted in FIG. 2.The seal member 74 completely covers the sealing support 184, bywrapping around the inner portion 188, the end tip 192, and the outerportion 190.

The sealing support 184 acts as a support structure between and againstwhich the radial seal 76 may be formed by the compressible seal member74. The compression of the compressible seal member 74 is preferablysufficient to form radial seal 76 under insertion pressures of nogreater than 80 lbs., typically, no greater than 50 lbs., for exampleabout 20-30 lbs., and light enough to permit convenient and easychange-out by hand. Preferably, the amount of compression of the sealmember 74 is at least 15%, preferably no greater than 40%, and typicallybetween 20 and 33%. By the term “amount of compression,” it is meant thephysical displacement of an outermost portion of the seal member 74radially toward the sealing support 184 as a percentage of the outermostportion of the seal member 74 in a resting, undisturbed state and notinstalled within the housing 51 or subject to other forces.

Attention is directed to FIG. 7. Preferably, the seal member 74 has astepped cross-sectional configuration of decreasing outermost dimensionsfrom a first end 194 to a second end 196 to achieve desirable sealing.Preferably, the seal member 74 will comprise a polyurethane foammaterial having a plurality (preferably, at least three) ofprogressively larger steps configured to interface with the secondannular region 104 (FIG. 2) and provide a fluid-tight seal. As can beseen in FIG. 7, the seal member 74 defines three steps 197, 198, and 199that increase in dimension between the second end 196 and the first end194. The smallest dimension at step 197 allows for easy insertion intothe body member 80. The largest dimension at step 199 ensures a tightradial seal 76.

In general, for a properly functioning radially sealing structure, thecompressible seal member 74 needs to be compressed when the element 52is mounted in the housing 51 (FIG. 2). In many preferred constructions,the seal member 74 is compressed between about 15% and 40% (often, about20-33%) of its thickness to provide for a strong robust seal, yet stillbe one that can result from hand installation of the element 52 withforces on the order of 80 lbs. or less, preferably 50 lbs. or less, andgenerally about 20-30 lbs.

Attention is directed to FIG. 6. The preferred frame 180 includes asupport system 205. During use of the filter element 52 depicted, inwardforces are exerted around the outer periphery of the frame 180. Inwardforces exerted against the curved ends 206, 208 can cause the straightsegments 210, 212 to bow or bend. The support system 205 is provided aspart of the frame 180 to prevent the straight segments 210, 212 frombowing. Further, the support system 205 also provides for engagement andconnection with the handle member 70.

While a variety of structures are contemplated herein, in the particularembodiment illustrated in FIG. 6, the support system 205 includes aplurality of cross braces 214 to provide structural rigidity and supportto the straight segments 210, 212. As can be seen in FIG. 6, the crossbraces 214 form a truss system 216 between the opposing straightsegments 210, 212. The truss system 216 includes a plurality of rigidmembers or struts 218, preferably molded as a single piece with theremaining portions of the frame 180.

As can also be seen in FIG. 6, the support system 205 providesengagement surfaces or members for the handle member 70 to connect with.This is described further below.

F. Handle Member

The handle member 70 is now described in further detail. Preferably, thehandle member 70 is secured to the filter element 52, and is constructedand arranged to accommodate a grasping force applied by portions of ahuman hand. This permits convenient manipulation and handling of thefilter element 52, particularly during servicing or changeout.

In preferred systems, the handle member 70 is secured to the element 52,such that a pulling force applied to the handle member 70 will translateinto a pulling force applied to the filter element 52. In most preferredsystems, the handle member 70 will be secured to a central core member230 (FIG. 2), such that portions of the fluted construction 122 will notneed to have obstructions or other connections made to accommodate thehandle member 70.

The handle member 70 is preferably integral with the core member 230.Further, in the preferred embodiment shown in FIG. 2, the handle member70 is molded as a single piece with the core 230. This single piecemolding permits expedient, convenient manufacturing and assembly.

In preferred embodiments, the handle member 70 will comprise a centerboard 232 (FIG. 8) for use in the filter element 52. Attention isdirected to FIG. 8. One preferred center board 232 is illustrated, intop plan view. The center board 232 depicted comprises an extension 234having a first end 236 and an opposite, second end 238. The handlemember 70 forms the first end 236, in the preferred embodiment shown. Afastening member 240 forms the second end 238. As briefly discussedabove, the fastening member 240 is constructed and arranged to connectto the frame 180.

By having the fastening member 240 engage and be secured to the frame180, the filter element 52 can be removed from the housing 51 bygrasping handle member 70, and without having the coiled flutedconstruction 122 forming the filter media of the element 52 be“telescoped.” In other words, by securing the handle member 70 to theframe 180, and in particular to the support system 205, when pullingforces are used on the handle member 70, the element 52 is preventedfrom being pulled out in a telescoping manner. That is, because of theengagement between the fastening member 240 and the support system 205,each of the inlet face 60 and outlet face 62 maintain a relatively flat,planar surface. The engagement between the fastening member 240 and thestruts 218 in the truss system 226 help to distribute the pulling forceexerted on the handle member 70 throughout the entire cross-section ofthe filter element 52. The pulling force on the first end 64 of theelement 52 is translated into a pulling force on the opposite, secondend 66 of the element 52, and axially across the cross-section of thesecond end 66 of the element 52.

Still in reference to FIG. 8, the center board 232 preferably includesfirst and second side edges 242, 244 extending between the first andsecond ends 236, 238.

While a variety of embodiments for fastening members 240 are possibleand contemplated herein, in the particular embodiment illustrated inFIG. 8, the fastening member 240 includes a hook construction 250. Thehook construction 250 is for catching portions of the braces 214 of thesupport system 205. In the example illustrated in FIG. 8, the hookconstruction 250 includes a first hook 252 cantilevered from theextension 234 and being along the first side edge 242, and a second hook254 cantilevered from the extension 234 and being along the second sideedge 244.

The first hook includes a recessed region 256 that forms a seat, and acornered shoulder 258. A surface 260 is angled from the shoulder 258 toreach an end point 262. Extending from the end point 262 is preferablyan edge 264 that extends inwardly, to define a cutout 266. In theembodiment shown, the cutout 266 is U-shaped. The cutout 266 permits thefirst hook 252 to deflect in a direction toward the second side edge244. The angled surface 260 abuts and slides along the braces 214, toallow for the deflection of the first hook 252, until the brace 214engages within the recessed region 256.

It should be appreciated that the deflection permitted by the cutout 266allows for convenient, quick engagement and connection between thecenter board 232 and flame 180. In particular, the first hook 252deflects in a direction toward the second side edge 244, which allowsone of the braces 214 to be seated within the recessed region 256 and betrapped by the cornered shoulder 258. Preferably, the deflection is atleast 1 mm, no greater than about 20 mm, and typically about 1.5-5 mm.

The second hook 254 is constructed analogously as the first hook 254. Assuch, the second hook 254 includes a recessed region 276 as a seat forholding the braces 214. The second hook 254 includes a cornered shoulder278, an angled surface 280, an end point 282, an edge 284, and aU-shaped cutout 286.

FIG. 7 shows the element 52 before the fastening member 240 has beensnapped or hooked into place with the support system 205 of the frame180. The filter element 52 is lowered into the flame 180, and the firstand second hooks 252, 254 are deflected inwardly or toward each other,until the recessed regions 256, 276 of the hooks 252, 254 are snapped orengaged into the braces 214.

Referring again to FIG. 8, the handle member 70 is now described infurther detail. Handle member 70 preferably includes at least oneprojection 290 axially extending from the first end 64 of the filterelement 52 (FIG. 2). Attention is directed to FIG. 2. As can be seen inFIG. 2, the first projection 290 is oriented closer to the first sideedge 242 than to the second side edge 244. In the particular preferredembodiment illustrated, the first projection 290 is even with the firstside edge 242. The first projection 290 preferably has an aperture 292extending therethrough to accommodate portions of a human hand, such asa few fingers.

There is also preferably a second projection 294 extending axially fromthe first end 64 of the filter element 52. The second projection 294 ispreferably spaced apart from the projection 290 by distance 100 (FIG. 2)in order to accommodate the extension 90 from the cover 82 of thehousing 51. The projection 294 preferably includes an aperture 296extending therethrough sized to accommodate portions of a human hand,such as a few fingers. It can be seen that the second projection 294 iscloser to the second side edge 244 than it is to the first side edge242. In the preferred embodiment illustrated, the second projection 294is even with the second side edge 244.

The center board 232 defines a recessed portion 298 (FIG. 8) extendingbetween the first projection 290 and second projection 294. The secondprojection 294 is preferably located between the first projection 290and the second side edge 244; similarly, the first projection 290 ispreferably located between the second projection 294 and the first sideedge 234. The preferred embodiment includes the recessed portion 298extending between the first projection 290 and the second projection294.

Preferably, the recessed portion 298 has a rigid, straight edge 300extending between and connecting the first and second projections 290,294. The edge 300 is used to engage and receive the projection 88 fromthe cover 82 (FIG. 2). In normal use, there is no engagement between theprojection 88 and the edge 300. If there is engagement, it may indicateto the user that the element 52 is not properly installed in the housing51. Engagement between the extension 90 and edge 300 will preventsecuring the cover 82 to the body member 80. During use, there can besome engagement, if the element 52 vibrates in the body member 80. Inthose instances, the extension 90 will help to hold the element 52 in aproperly installed position (with the radial seal 76 in place). Theextension 90 is properly oriented in the void 100 created by therecessed portion 298.

Referring again to FIG. 8, there is preferably a system 305 for helpingto hold the fluting sheet 130 in place, to prevent slippage and bowingoutwardly, during assembly. In the illustrated embodiment, this system305 is integral with the center board 232. In particular, the centerboard 232 includes a region of corrugations 310 located on the extension234 between the first and second ends 236, 238. The region ofcorrugation 310 is preferably constructed and arranged to mate withflutes 124 of the fluted sheet 130, during construction and assembly ofthe filter element 52. When initially assembling the filter element 52,the fluted sheet 130 is wound around the center board 232. In someapplications, the fluted sheet 130 will have a memory built in, andinherently will want to bow outwardly, radially in a direction away fromthe center board 232. It becomes difficult to create a secure, tightseal, when this is occurring. To rectify this, the region ofcorrugations 310 is in the center board 232, because the fluted sheet130 is better able to mate and engage with the center board 232, thanwith a flat surface.

In reference now to FIG. 9, the region of corrugation 310 preferablyincludes a plurality of corrugations 312. In particular, the pluralityof corrugations includes a plurality of peaks 322 alternating with aplurality of troughs 324. In the embodiment illustrated in FIG. 8, thecorrugations 312 extend continuously between the first edge 242 and thesecond edge 244. In preferred embodiments, there will be at least 5peaks 322 and 5 troughs 324; no more than about 100 peaks 322 and nomore than about 100 troughs 324; and preferably between 10-50 peaks 322and about 10-50 troughs 324. The corrugations 312 also help to preventslippage of the fluted sheet 130 relative to the center board 232,during winding. In other words, the region of corrugation 310 provides abearing surface to help hold and secure the fluted sheet 130 to thecenter board 232 during winding and manufacturing.

Note that in the embodiment of FIG. 8, the region of corrugations 310extends only partially along the length of the extension 234.Preferably, the length of the region or corrugations 310 will extend atleast 1 inch downwardly from the edge 300. In other embodiments, theregion of corrugations 310 can extend the entire length between the edge300 and an opposite edge 314 at the second end 238. Some minimal lengthof the corrugations 310 is desired because the adhesive securing thefluted sheet 130 and the center board 232 will extend only a partialdistance along the center board 232. But, the region of corrugations 310can also extend the entire length between the edge 300 and edge 314,because the corrugations 312 provide a bearing surface for winding thefluted sheet 130 around the center board 232.

During construction of the filter element 52, the center board 232 maybe placed on a spindle and held at cutout 316. Adhesive is placed alongthe region of corrugations 310, and the fluted sheet 130 is placed overthe adhesive. The flutes 124 mate with the individual corrugations 312of the center board 232. The center board 232 is then turned about acentral axis, while the fluted construction 122 is formed around thecenter board 232.

The individual corrugations 312 can be a variety of sizes. Preferredcorrugations 312 will be of a size to mate with the individual flutes inthe fluted sheet 130. One size includes: a peak to peak width 326 ofabout 5-7 mm, for example, about 6.5 mm; a trough to peak height 328 ofabout 1-4 mm, for example, about 2.5 mm; a radius on each peak, 322 ofabout 0.5-2 mm, for example, about 1 mm; a radius on each trough 324 ofabout 1-3 mm, for example, about 1.3 mm; a peak to peak depth 330 ofabout 6-10 mm, for example, about 7.9 mm; and a trough to trough width332 of about 5-8 mm, for example, about 6 mm.

Another size includes: a peak to peak width 326 of about 6-10 mm, forexample, about 8.4 mm; a trough to peak height 328 of about 2-6 mm, forexample, about 4.3 mm; and a trough to trough width 332 of about 6-10mm, for example, about 8.4 mm.

Another size includes: a peak to peak width 326 of at least 5 mm, nogreater than 9 mm—for example, about 7.6 mm; a trough to peak height 328of at least 2 mm, no greater than 5 mm—for example, about 3.3 mm; a peakto peak depth 330 of at least 1 mm, no greater than 6 mm—for example,about 3.3 mm; and a trough to trough width 332 of at least 4 mm, nogreater than 10 mm—for example, about 7.6 mm.

Referring again to FIG. 8, the preferred center board 232 includes aplurality of apertures or holes 320. The holes 320 help to create alightweight center board 232. The holes 320 can be in any pattern.

G. Methods of Operating, Servicing, and Assembling

In operation, gas to be cleaned, such as airflow being taken intoequipment 22, will be initially sucked into the air cleaner 50 anddirected through inlet 56. The air will then flow through the inlet face60 of the filter element 52. The air will enter the flute chambers 136that are opened at the upstream end 64. The air will be forced to flowthrough either the fluting sheet 130 or the face sheet 132, and as such,have particulates removed therefrom. The cleaned air will then exit atthe outlet face 62. That is, the cleaned air will exit through theflutes 134 that are open at the second end 66. The cleaned air will thenflow through the outlet 58, and be directed to downstream components,such as engine 24. The uncleaned air is prevented from bypassing thefilter element 52 by the radial seal 76 between the filter element 52and the housing 80.

After a certain period of operation, the air cleaner 50 will requireservicing. The filter element 52 will become occluded and requirereplacing. Typically, the filter element 52 should be removed andreplaced when the restriction reaches at least 25 inches of water. Toservice the air cleaner 50, the cover 82 is removed from the body member80. This is done by removing the bolts 86 and then removing the coverfrom the body member 80 to expose the opening 84. This provides accessto the interior 54 of the body member 80. When the cover 82 is removedfrom the body member 80, the element engaging end 96 of the extension 90is removed from the void 100 of the recessed portion 298 of the handlemember 70.

Next, the user grasps the filter element 52. Preferably, this is done bygrabbing the handle member 70. In the preferred embodiment, this is doneby inserting at least one finger of one hand in the aperture 292, andanother finger of the other hand in aperture 296. The user then appliesa pulling force to the handle member 70. This translates into a pullingforce on the extension 234, and ultimately onto the frame construction72. That is, the pulling force is transferred through the fasteningmember 240 to the support system 205. The pulling force will move thefilter element 52 in an axial direction, such that the seal member 74moves from the second annular region 104 to the first annular region102. This breaks the radial seal 76.

The filter element 52 is then removed through the opening 84 outside ofthe air cleaner 50. The old filter element 52 may then be disposed of.This may be accomplished by incinerating the entire filter element 52,including the center board 232. Alternatively, the fluted mediaconstruction 122 may be separated from the center board 232, such thatthe center board 232 may be reused. Or, alternatively, after the flutedconstruction 122 is removed from the center board 232, each can bedisposed of in separate recycling programs.

A second, new, filter element 52 is then supplied. The new filterelement 52 is inserted through the opening 84 of the body member 80. Theuser may manipulate the filter element 52 by grasping the handle member70, through its projections 290, 294. The filter element 52 is insertedinto the housing 51, until the radial seal 76 is formed. In theillustrated embodiment, this is done by pushing the filter element 52into the body member 80, until the end 196 of the seal member 74 abutsor engages the end wall 108 of the second annular region 104.

The cover 82 is then oriented over the open end 84. As this is done, theextension 90 is lowered into the interior 54. If the filter element 52has not been properly seated within the seat of the annular region 104,the extension 90 will engage the edge 300 of the handle member 70 andprevent the cover 82 from being properly seated on the body member 80.If the filter element 52 is properly seated within the seat of theannular region 104 (and the radial seal 76 is in place), then the cover82 will be permitted to properly fit onto the body member 80. Theextension 90 will rest in the void 100. The cover 82 is then secured tothe body member 80, by tightening the bolts 86. The air cleaner 50 isthen ready to be operated again.

To construct preferred filter elements 52 as described herein, first,the center board 232 is provided. The center board 232 may be made usingconventional techniques, such as injecting molding.

Next, adhesive is applied to the region of corrugations 310. In thepreferred embodiment of FIG. 8, adhesive is applied only to a portion ofthe region of corrugations 310. In particular, adhesive is applied onlyalong about the upper one-third of the region of corrugations 310,completely between edge 242 and edge 244. By “upper portion,” it ismeant the portion that is closer to the handle member 70 than to thefastening member 240. In other embodiments, the adhesive can be alongthe entire length of the region of corrugations 310, or less than theupper one-third, for example, the upper 10-25%. It should be noted thatadhesive is applied on both top and bottom sides of the region ofcorrugation 310 of the center board 232.

The fluting sheet 130 is then laid over the center board 232. Individualflutes of the fluting sheet 130 are mateably engaged with individualcorrugations 312 of the region of corrugation 310. The adhesive joinsthe fluting sheet 130 to the extension 234. The fluting sheet 130 iswrapped around the center board 232 completely. In other words, thefirst layer of the fluting sheet 130 will completely circumscribe boththe top and bottom side of the center board 232. The region ofcorrugations 310 will help to keep the fluting sheet 130 tightly againstthe center board 232. The region of corrugations 310 will also provide abearing surface to help wind the fluted construction 122 therearound.

Preferably, the center board 232 is held at notch 316 by the spindle ofa machine. The machine spindle will turn the center board 232 about itscentral longitudinal axis, to wind the fluting sheet 130 and face sheet132 around the center board 232.

After the fluted construction 122 is wound around the center board 232,the center board 232 is secured to the frame construction 72. Inpreferred embodiments described herein, the fastening member 240 isconnected or secured to the braces 214 of the support system 205. Thisis done by lowering the center board 232 with the media construction 122secured thereto into the frame 180. The angled surfaces 260, 280 willcam or be pushed against the braces 214. The cutouts 266, 286 will allowthe hooks 252, 254 to deflect inwardly, toward each other. The corneredshoulders 258, 278 will then snap over the braces 214. This will trapthe braces 214 into the recesses 256, 276. Typically, before thecenterboard 232 is connected to the frame 180, adhesive will be appliedalong the inner surface of the lip 182, to secure the outer layer 170 tothe lip 182 of the frame 180. The filter element 52 may then beinstalled in the air cleaner housing 51.

H. Example Materials and Dimensions

The following section includes usable materials and dimensions ofspecific embodiments. Of course, a wide variety of materials anddimensions may be utilized.

Preferably, the housing 51 is constructed of plastic, for example glassfilled nylon. The extension 90 will have a length of at least about 50mm, and no greater than about 500 mm. The extension 90 will have a width98 of at least about 5 mm, no greater than about 50 mm, and typicallyabout 10-40 mm. As a percentage of the distance 100, the width 98 of theextension 90 will be at least about 10%, no greater than 95%, andtypically about 25-75% of the distance 100.

The filter element 52 will have an overall length extending between itsinlet face 60 and outlet face 62 of at least about 100 mm, no greaterthan about 500 mm, and typically about 200-300 mm. It will have a majordimensional width of at least about 100 mm, no greater than about 400mm, and typically about 200-300 mm. It will have a minor dimensionalwidth of at least about 25 mm, no greater than about 250 mm, andtypically about 50-150 mm.

The filter element 52 can be constructed of cellulose. One example ofusable cellulose media is: a basis weight of about 45-55 lbs./3000 ft²(84.7 g/m²), for example, 48-54 lbs./3000 ft²; a thickness of about0.005-0.015 in, for example about 0.010 in. (0.25 mm); frazierpermeability of about 20-25 ft/min, for example, about 22 ft/min (6.7m/min); pore size of about 55-65 microns, for example, about 62 microns;wet tensile strength of at least about 7 lbs/in, for example, 8.5lbs./in (3.9 kg/in); burst strength wet off of the machine of about15-25 psi, for example, about 23 psi (159 kPa). The cellulose media canbe treated with fine fiber, for example, fibers having a size (diameter)of 5 microns or less, and in some instances, submicron. A variety ofmethods can be utilized for application of the fine fiber to the media.Some such approaches are characterized, for example, in U.S. Pat. No.5,423,892, column 32, at lines 48-60. More specifically, such methodsare described in U.S. Pat. Nos. 3,878,014; 3,676,242; 3,841,953; and3,849,241, incorporated herein by reference. An alternative is a tradesecret approach comprising a fine polymeric fiber web positioned overconventional media, practiced under trade secret by Donaldson Companyunder the designation ULTRA-WEB®. With respect to the configurations ofthe filter element, there is no particular preference for: how the finefibers are made; and, what particular method is used to apply the finefibers. Enough fine fiber would be applied until the resulting mediaconstruction would have the following properties: initial efficiency of99.5% average, with no individual test below 90%, tested according toSAE J726C, using SAE fine dust; and an overall efficiency of 99.98%average, according to SAE J726C.

The center board 232 will have an overall length of at least about 100mm, no greater than about 800 mm, and typically about 200-500 mm. Itwill have an overall width between side edge 242 and side edge 244 of atleast about 50 mm, no greater than about 500 mm, and typically about100-200 mm. Each of the projections 290, 294 will extend above the firstend 64 by a distance of at least about 20 mm, no greater than about 200mm, and typically about 40-100 mm. The distance 100 between the insideedges of the projections 290, 294 is at least about 25 mm, no greaterthan about 300 mm, and typically about 50-150 mm. Each of the apertures292 will have an outermost dimension (preferably, a diameter) of atleast about 10 mm, no greater than about 150 mm, and typically about20-70 mm.

The length of the region of corrugations 310 will preferably be at leastabout 20 mm, no greater than about 200 mm, and typically about 50-100mm. There will preferably be at least 5, no greater than about 100, andtypically about 10-30 individual corrugations 312.

Each of the angled surfaces 260, 280 on the hooks 252, 254 will extendat an angle relative to the central longitudinal axis of the centerboard 232 of at least about 30°, no greater than about 60°, andtypically about 40-50°. Each of the recesses 256, 276 will have a widthof at least about 4 mm, no greater than about 25 mm, and typically about5-15 mm. Each of the cutouts 266, 286 will extend at least about 10 mm,no greater than about 80 mm, and typically about 20-50 mm from thebottom edge 314.

The center board 232 will have an overall thickness of at least about 1mm, no greater than about 20 mm, and typically about 2-10 mm. The centerboard 232 will have an overall weight of at least about 2 oz., nogreater than about 10 oz., and typically about 4-6 oz. There will be atleast 1 hole 320, no greater than about 100 holes 320, and typicallyabout 25-35 holes 320. Preferably, the center board 232 will beconstructed of plastic, such as glass filed nylon, preferably 13% glassfilled nylon.

Preferably, the frame 180 will be constructed from plastic, such as 33%glass filled nylon. The seal member 74 can be constructed from foamedpolyurethane having an as molded density of about 11-22 lbs/ft³. Oneusable foamed polyurethane is described in U.S. Pat. No. 5,669,949,incorporated herein by reference.

The above specification, examples, and data provide a completedescription of the manufacture and use of the invention. Manyembodiments of the invention can be made.

We claim:
 1. A filter arrangement comprising a filter element havingopposite first and second ends; said filter element comprising aplurality of flutes; each of said flutes having a first end portionadjacent to said filter element first end, and a second end portionadjacent to said filter element second end; selected ones of said flutesbeing open at said first end portion and closed at said second endportion; and selected ones of said flutes being closed at said first endportion and open at said second end portion; and a frame constructionsecured to said filter element adjacent to said second end; the filterarrangement being characterized by: (a) a handle member is secured tosaid filter element adjacent to said first end; (b) a board is at leastpartially extending into said filter element; said board including: (i)first and second opposite ends; (ii) first and second opposite sideedges extending between said board first and second opposite ends; (iii)a first projection axially extending from said first end of said filterelement; (A) said first projection being oriented closer to said firstside edge than to said second side edge; and (iv) a recessed portionadjacent to said first projection; and (c) said frame constructionincludes at least one support brace extending at least partially overone of said first and second ends of said filter element.
 2. A filterarrangement according to claim 1 wherein: (a) said handle member issecured to said frame construction.
 3. A filter arrangement according toclaim 2 wherein: (a) said frame construction includes a plurality ofsupport braces extending at least partially over one of said first andsecond ends of said filter element; and (b) said handle member includesa pair of hooks engaging said support braces.
 4. A filter arrangementaccording to claim 2 wherein: (a) said frame construction includes anextension projecting axially from one of said first and second ends; (i)said extension of said frame construction supporting a seal member.
 5. Afilter arrangement according to claim 4 wherein: (a) said extensionincludes an inner portion, an outer portion, and an end tip; (b) saidseal member comprises polyurethane having an as molded density of 11-22lbs/ft³; (i) said seal member covering at least part of said outerportion, said inner portion, and said end tip of said extension.
 6. Afilter arrangement according to claim 4 wherein: (a) said seal memberdefines a cross-sectional configuration of steps.
 7. A filterarrangement according to claim 2 wherein: (a) said board comprises acentral core member; said plurality of flutes being coiled around saidcentral core member.
 8. A filter arrangement according to claim 7wherein: (a) said handle member is secured to said central core member.9. A filter arrangement according to claim 8 wherein: (a) said handlemember and said central core member are a single-molded construction.10. A filter arrangement according to claim 7 wherein: (a) said centralcore member includes a plurality of corrugations; said corrugationsmateably engaging at least some of said flutes.
 11. A filter arrangementaccording to claim 7 wherein: (a) said handle member comprises at leasta single aperture defined by said central core member.
 12. A filterarrangement according to claim 11 wherein: (a) said central core memberincludes first and second opposite ends; (i) said handle member beingpart of said first end of said central core member, and projecting fromsaid first end of said filter element; and (ii) a hook constructionbeing part of said second end of said central core member; (A) said hookconstruction engaging said frame construction.
 13. A filter arrangementaccording to claim 1 wherein: (a) said board further includes a secondprojection axially extending from said first end of said filter element;(i) said second projection being located between said first projectionand said second side edge; and (ii) said recessed portion extendingbetween said first projection and said second projection.
 14. A filterarrangement according to claim 13 wherein: (a) said recessed portioncomprises a straight segment of said board along said board first end;(b) said first projection is immediately adjacent to said first sideedge; and (c) said second projection is immediately adjacent to saidsecond side edge.
 15. A method for servicing an air cleaner; the methodcomprising providing a filter element installed in a housing, whereinthe filter element includes opposite upstream and downstream ends; thefilter element having a plurality of flutes, each of the flutes having afirst end portion adjacent to the filter element upstream end, and asecond end portion adjacent to the filter element downstream end;selected ones of the flutes being open at the first end portions andclosed at the second end portions, and selected ones of the flutes beingclosed at the first end portions and open at the second end portions;the filter element further including a frame construction securedthereto; the method being characterized by: (a) grasping a handleprojecting from one of the upstream and downstream ends; the handlebeing secured to the frame construction; (b) pulling the handle toremove the filter element from the housing; (c) providing a secondfilter element; the second filter element having an axial projectionextending therefrom and a recessed portion adjacent to the axialprojection; (d) orienting the second filter element in the housing; and(e) orienting a stay member in the recessed portion.
 16. A methodaccording to claim 15 wherein: (a) the housing includes a body memberand a cover; and (b) said step of orienting a stay member includesplacing the cover over the body member; the stay including a projectionextending from the cover.
 17. A method according to claim 15 wherein:(a) said step of providing a second filter element includes providing asecond filter element including opposite upstream and downstream ends;the second filter element having a plurality flutes, each of the fluteshaving a first end portion adjacent to the second filter elementupstream end, and a second end portion adjacent to the second filterelement downstream end; selected ones of the flutes being open at thefirst end portions and closed at the second end portions, and selectedones of the flutes being closed at the first end portions and open atthe second end portions; the second filter element further including aframe construction secured thereto, and a handle.
 18. A method accordingto claim 17 wherein: (a) said step of providing a second filter elementincludes providing a second filter element having a central core; (i)the handle being secured to the central core; and (ii) the handlecomprising at least a portion of the axial projection.
 19. A methodaccording to claim 17 wherein: (a) said step of providing a secondfilter element includes providing a second filter element having a boardat least partially extending into the second filter element; the boardincluding: (i) first and second opposite ends; (ii) first and secondopposite side edges extending between the board first and secondopposite ends; (iii) the axial projection extending from the board firstend; and (iv) the recessed portion comprising a segment of the boardalong the board first end.
 20. A method according to claim 15 furthercomprising: (a) forming a seal between the second filter element and thehousing.
 21. A filter arrangement comprising a filter element havingopposite first and second ends; said filter element comprising aplurality of flutes; each of said flutes having a first end portionadjacent to said filter element first end, and a second end portionadjacent to said filter element second end; selected ones of said flutesbeing open at said first end portion and closed at said second endportion; and selected ones of said flutes being closed at said first endportion and open at said second end portion; the filter arrangementcomprising: (a) a frame construction secured to said filter elementadjacent to said second end; and (b) a board is at least partiallyextending into said filter element; said board including: (i) first andsecond opposite ends; (ii) first and second opposite side edgesextending between said board first and second opposite ends; (iii) ahandle member comprising a first projection axially extending from saidfirst end of said filter element; (A) said first projection beingoriented closer to said first side edge than to said second side edge;and (iv) a recessed portion adjacent to said first projection.
 22. Afilter arrangement according to claim 21 wherein: (a) said frameconstruction includes at least one support brace extending at leastpartially over one of said first and second ends of said filter element;and (b) said board engages said at least one support brace.
 23. A filterarrangement according to claim 22 wherein: (a) said frame constructionincludes an extension projecting axially from one of said first andsecond ends; (i) said extension of said frame construction supporting aseal member.
 24. A filter arrangement according to claim 23 wherein: (a)said extension includes an inner portion, an outer portion, and an endtip; (b) said seal member comprises polyurethane; (i) said seal membercovering at least part of said outer portion, said inner portion, andsaid end tip of said extension.
 25. A filter element according to claim21 wherein: (a) said board further includes a second projection axiallyextending from said first end of said filter element; (i) said secondprojection being located between said first projection and said secondside edge; and (ii) said recessed portion extending between said firstprojection and said second projection.
 26. A filter element according toclaim 21 wherein: (a) said handle member comprises at least a singleaperture through said first projection of said board.
 27. A filterelement according to claim 26 wherein: (a) said recessed portioncomprises a straight segment of said board along said board first end;(b) said first projection is immediately adjacent to said first sideedge; and (c) said board includes a second projection immediatelyadjacent to said second side edge; (i) said second projection having atleast a single aperture to further comprise said handle member.